Abstract

Flow Control and Configurable Microstructures Using Non-Uniform Electroosmosis

Moran Bercovici, Assistant Professor, Technion – Israel Institute of Technology

Electro-osmotic flow (EOF) is the motion of a liquid due to interaction of an externally applied electric field with the net charge in the diffuse part of an electrical double layer.  
I will present our ongoing work leveraging non-uniform EOF to control flow patterns in a Hele-Shaw microfluidic chamber (two parallel plates separated by a small gap).  By setting the spatial distribution of surface potential, we demonstrate the ability to dictate desired flow patterns without the use of physical walls. Furthermore, by replacing the rigid ‘ceiling’ (top plate) of the chamber with a thin elastic sheet, we demonstrate that internal pressure gradients formed in the liquid can be used to drive local deformations in the sheet.  This opens the door to the implementation of configurable microstructures and microfluidic devices. In addition to experimental demonstrations, I will present key elements of the analytical models we developed, and discuss both future applications and limitations of the technology.